               
                 *** Homebrew Interface Schematic by IW3FQG ***

       +5V <-----------o------------------o----+           C = 10uF
                       |                  |    |           IC1 = 7404
                       |              C | = |  |           IC2 = MAX232
                       |                +-+-+  |
                    14 |                2 |  16|
   T              +----------+       +------------+
   R    2  <------| 1      2 |-------|11        14|----------------> 3
   A              |    I     |       |     I      |                       R
   N    3  <------| 4  C   3 |-------|12   C    13|----------------> 2    S
   S              |    1     |       |     2      |
   C    4  <------| 6      5 |-------| 9         8|----------------> 5    2
   E              |          |       |            |                       3
   I    5  <------| 9      8 |-------|10         7|----------------> 4    2
   V              +----------+       |           4|------+
   E                   | 7        +--|1 3  6  15 5|-+    |       +-> 7    C
   R     1  <--+        |          |  +------------+ |    |       |       O
              |      /////    C | = |  |   |   |    |  | = | C   |        M
            /////               +-+-+  | | = | |    |  +-+-+    ///       P
                                  |    | +-+-+ |    |    |                O
                                  +----+ C |   |    +----+                R
                                          ///////                         T

 
 1990 IW3FQG
